The time for taking methylcobalamin for numbness in the little finger due to ulnar nerve damage is mainly judged according to the recovery of the patient’s condition, which usually takes about 1~2 months. Methylcobalamin capsule is a kind of vitamin drugs, can promote the utilization of folic acid and nucleic acid metabolism, so that the neurotransmitters return to normal, relieve the patient’s numbness symptoms. Ulnar nerve damage caused by numbness in the little finger taking methylcobalamin, mainly based on the patient’s condition, the drug sensitivity to make a decision, most need to be taken orally for about 1~2 months to have an effect. When taking methylcobalamin orally, note that patients who are allergic to methylcobalamin or its excipients should not take it, and after oral intake, pay attention to the observation of adverse reactions to the drug, which can occasionally be seen in the gastrointestinal tract, hives, rash and other allergic conditions. For patients with ulnar nerve damage, it is recommended to consult the neurosurgery department of regular hospitals, and the drug should be used under the guidance of doctors.